Klaus Halbach,Undulator Pioneer

I am indebted to Karl Brown for suggesting that I invite Klaus, who I did not know at the time, to a workshop on wiggler magnets in March 1977. I recall Karl saying to me something like, “Herman, if you want someone who knows about magnets, you should invite Klaus Halbach.” Klaus came and even made a contribution about some aspects of the design of electromagnet wigglers, the only type of wigglers that had been considered to that time. However, it was at that workshop that Klaus got his introduction to synchrotron radiation, mostly by listening to talks by Albert Hofmann and Andy Sesler, who explained the marvelous properties of undulator magnets as radiation sources. Klaus filed this information in his long-term memory banks while working on other topics, particularly the design of permanent magnet quadrupoles for proton linacs.     

Biosensors: Internet Information Resources

The state of the art in the Internet information resources for biosensors is considered, and the classification of the websites is given     

A potentiometric DNA sensor for determining autoimmune antibodies to DNA

A new technique is proposed for detecting interactions between DNA and DNA autoimmune antibodies using a potentiometric sensor based on a glassy-carbon electrode modified with polyaniline and native DNA from chicken erythrocytes. It is shown that the DNA-antibody interaction changes the rate of polyaniline doping in transferring the DNA sensor from an alkaline (pH 7.5) solution, which is optimum for the immunochemical reaction, to an acidic (pH 3.0) solution. The dynamics of the variation of the DNA sensor potential depends on the titer of antibodies and their origin. The dependence of the DNA sensor signal on the dilution of the blood sera from systemic lupus erythematosus and autoimmune thyroiditis patients shows that DNA antibodies can be diagnosed by the characteristic maximum in the dilution curve found in the range of serum dilutions from 1: 20 to 1: 50.     

Determination of Ascorbic Acid by Electrocatalytic Response of an Electrode Coated with Polyvinylpyridine Film and Palladium-Plated

A procedure was developed for analysis of ascorbic acid with a carbon glass electrode coated with a palladium-modified poly(2-vinylpyridine) film.     

Optimization for pattern classification using biased random search techniques

We demonstrate how optimization problems arise in the field of pattern classification, in particular in using piecewise-linear classification and classification based on an optimal linear separator. We motivate the need in this area for a general purpose optimization approach. We discuss ALOPEX, a biased random search approach, from the point of view of this need. While ALOPEX itself failed to fulfil our need, a newly-introduced generalization of it (iterated ALOPEX) was found to be appropriate for the optimization problems of our particular concern. We conclude the paper with a brief critical evaluation of this approach as compared to our original aims.     

Voltammetric determination of papaverine and drotaverine

Isoquinoline derivatives (papaverine and drotaverine) are oxidized at a graphite electrode in a 0.1 M sulfuric acid solution to give voltammetric waves at 1.1 V for papaverine and at 1.05 and 1.28 V for drotaverine. Determination limits and linearity ranges of currents as functions of papaverine and drotaverine concentrations are estimated. Microgram amounts of papaverine and drotaverine are determined in model solutions (RSD = 1–4%). A procedure for the direct determination of papaverine and drotaverine in pharmaceuticals is proposed.     

C=1 conformal field theories on Riemann surfaces

We study the theory ofc=1 torus and ₂-orbifold models on general Riemann surfaces. The operator content and occurrence of multi-critical points in this class of theories is discussed. The partition functions and correlation functions of vertex operators and twist fields are calculated using the theory of double covered Riemann surfaces. It is shown that orbifold partition functions are sensitive to the Torelli group. We give an algebraic construction of the operator formulation of these nonchiral theories on higher genus surfaces. Modular transformations are naturally incorporated as canonical transformations in the Hilbert space.     

Commutator-finite orthomodular lattices

The class of orthomodular lattices which have only finitely many commutators is investigated. The following theorems are proved: contains the block-finite orthomodular lattices. Every irreducible element of is simple. Every element of is a direct product of a Boolean algebra and finitely many simple orthomodular lattices. The irreducible elements of which are modular, or are M-symmetric with at least one atom, have height two or less.     

Enzymatic polymerizations using surfactant microstructures and the preparation of polymer-ferrite composites

Applied Biochemistry and Biotechnology - Horseradish peroxidase has been used as a biocatalyst to synthesize a polymeric material from alkyl-substituted phenols. The synthesis is carried out in a...